A dynamical model for post-translational modifications of microtubules.

In many cases, post-translational modifications constitute indirect markers of non-dynamic microtubules. The correlation between stability of microtubular systems and post-translational modifications suggests that they may act as a signal in patterning mechanisms. However, a crucial question remains as to how the repertoire of distinctly modified microtubules is generated. We propose here an ubiquitous mechanism of spatial and temporal differentiation of microtubules. In this model, the diversity of post-translational modifications results from a dynamical pathway separation which is ensured by biochemical switches between self-regulated mechanisms of differentiation. Thus, it does not require any hypothetical subcellular compartmentalization of enzymatic activities responsible for the various post-translational modifications. These results are discussed in relation to experimental evidences for a temporal and spatial regulation of microtubule modifications.